The visual system is highly skilled at recovering the shape of complex objects defined exclusively by motion cues. But while low-level and high-level mechanisms involved in shape-from-motion have been studied extensively, intermediate computational stages remain poorly understood. In the present study, we used motion-defined radial-frequency contours--or motion RFs--to probe intermediate stages...

The Institute for the Protection and Security of the Citizen of the EC Joint Research Centre (IPSC-JRC) has beenmandated to perform a study on the Radio Frequency (RF) threat against telecommunications and ICT controlsystems. This study is divided into two parts. The rst part concerns the assessment of high energy radio frequency(HERF) threats, where the focus is on the generation o...

Glass patterns are textural moirés from random dots. Sequential presentation of Glass patterns induces a sense of illusory motion. We evaluated how changes in temporal frequency affected the detection of global form in Glass patterns. We found linear improvement in coherence thresholds with increasing temporal frequency (Experiment 1), particularly in stimuli with large dot-pair separations (Ex...

For over 1000 years electromagnetic radiation has been utilized for long-distance communication. heliographs, telegraphs, telephones and radio have all served our previous communication needs. Nevertheless, electromagnetic radiation has one major difficulty: it is easily absorbed. In this paper we consider a totally different radiation, a radiation that is not easily absorbed: gravitational rad...

In this paper, an over-sampled periodogram higher criticism (OPHC) test is proposed for the global detection of sparse periodic effects in a complexvalued time series. An explicit minimax detection boundary is established between the rareness and weakness of the complex sinusoids hidden in the series. The OPHC test is shown to be asymptotically powerful in the detectable region. Numerical simul...

In a previous article (Papaphilippou&Laskar 1996), we used the frequency map analysis for studying the dynamics of the axisymmetric softened version of the logarithmic potential. The method is now applied to its 3-dimensional generalisation in order to deepen our knowledge regarding the dynamics of triaxial power-law galactic models. The principal dynamical features of the system are reviewed w...

Ultrashort laser pulses have thus far been used in two distinct modes. In the time domain, the pulses have allowed probing and manipulation of dynamics on a subpicosecond time scale. More recently, phase stabilization has produced optical frequency combs with absolute frequency reference across a broad bandwidth. Here we combine these two applications in a spectroscopic study of rubidium atoms....

We design pilot symbol assisted modulation for carrier frequency offset (CFO) and channel estimation in orthogonal frequency division multiplexing (OFDM) transmissions over multi-input multi-output (MIMO) frequency-selective fading channels. By separating CFO and channel estimation from symbol detection, the novel training patterns lead to low-complexity CFO and channel estimators. The performa...

Information retrieval (IR) in peer-to-peer (P2P) networks, where the corpus is spread across many loosely coupled peers, has recently gained importance. In contrast to IR systems on a centralized server or server farm, P2P IR faces the additional challenge of either being oblivious to global corpus statistics or having to compute the global measures from local statistics at the individual peers...

The recent destruction due to hurricanes and the apparent increase in frequency in the southeastern United States, especially in 2005 season, has prompted many scientists to study possible causes of these changes. Some scientists believe that global warming and increased sea surface temperatures are to blame. Warm water holds more energy to fuel hurricanes and may contribute to the conditions n...